Cita APA (7a ed.)

Oppenheim, E. P. (1923). The seven conundrums. Little, Brown, and Co..

Cita Chicago Style (17a ed.)

Oppenheim, E. Phillips. The Seven Conundrums. Boston: Little, Brown, and Co., 1923.

Cita MLA (8a ed.)

Oppenheim, E. Phillips. The Seven Conundrums. Little, Brown, and Co., 1923.